Locator actuation apparatus

ABSTRACT

An apparatus for locating a workpiece on a processing surface includes a first locator arm assembly, a second locator arm assembly, and a pivotal member. The first locator arm assembly includes a first surface disposed for lateral movement and mating engagement with a first portion of the workpiece. The second locator arm assembly includes a second surface disposed for lateral movement parallel to the first surface, the second surface further for mating engagement with a second, opposite side, portion of the workpiece. Lastly, pivotal member is disposed for pivotal movement about a pivot point and symmetrically coupled, with a zero tolerance buildup, between the first locator arm assembly and the second locator arm assembly for inducing an equal but opposite lateral movement in the first and second mating engagement surfaces of the first and second locator arm assemblies, respectively, whereby the workpiece is accurately located on the processing surface between respective first and second mating engagement surfaces as the surfaces are moved towards one another.

CROSS-REFERENCE TO COPENDING APPLICATIONS

Copending U.S. patent applications Ser. No. 08/840,835, filedconcurrently herewith, entitled "Substrate Tester Method and ApparatusHaving Rotatable and Infinitely Adjustable Locator Jaws", (Attorneydocket FI9-97-021) describes a locator actuation method and apparatusfor locating and positioning a substrate during manufacture and testingthereof; Ser. No. 08/840,836, filed concurrently herewith, entitled"Substrate Tester Having Shorting Pad Actuator Method and Apparatus",(Attorney docket FI9-97-022), describes a substrate tester; and Ser. No.08/840,834, filed concurrently herewith, entitled "Substrate TesterLocation Clamping, Sensing, and Contacting Method and Apparatus",(Attorney docket FI9-97-023) describes a glass ceramic substrate tester,all assigned to the assignee of the present invention, the disclosuresof which are hereby incorporated by reference into the presentapplication.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to a method and apparatus for locatingand positioning a workpiece on a surface and, more particularly, to alocator actuation method and apparatus for locating and positioning of amultilayer ceramic substrate (MLC) during a manufacture and testingthereof.

2. Discussion of the Related Art

Substrate testers are known in the art for performing network integritytests on substrates, such as multilayer ceramic substrates (MLCs). Asubstrate refers to a packaging unit that provides an interface betweena semiconductor chip (e.g. a very large scale integrated (VLSI) circuitchip) and a higher level packaging unit (e.g., a printed circuit board).A network is generally defined by a set of one or more electricallyconnected common points on a substrate. Networks are used to distributeelectrical signals and voltages externally and/or internally about thesubstrate in accordance with the requirements of a particular integratedcircuit chip. Substrate testers are used during substrate manufacturingto guarantee that there are no process or design created defects(corresponding to opens or shorts) on a particular substrate beingtested. Typically, a substrate tester performs a test using a particularcontacting scheme. A test matrix scanner is then used to provide anelectrical stimulus on each point of the networks contacted by thecontacting scheme and then systematically scans the remaining points inthe test matrix to guarantee all desired connections exist (opens test)and that there are no unwanted connections (shorts), as the case may be.

In current manufacturing techniques of MLC substrates, there is a needto improve the accuracy and cost structure of substrate locators in aneffort to satisfy more stringent manufacturing process requirements.Conventional substrate locators require many moving parts whichdisadvantageously contribute to tolerance build-ups, inaccuracies, andthus higher manufacturing costs. Conventional substrate locators alsouse many high precision parts, which are not performance efficient orcost efficient for meeting the current manufacturing requirements. Forexample, multi-cam drive assemblies are exceedingly costly in terms oftheir use in the manufacturing process.

Current state of the art substrate locators include a number of movingparts, which may include parts such as precision cam slots, camfollowers, gears, etc. The moving parts contribute to a build up oftolerances. This build up of tolerances prevents a precise and absolutelocating and positioning by the locator with respect to a centering ofthe substrate parts over or under a workstation, wherein the workstationrequires extreme positioning accuracy and repeatability. The workstationmay also include a high speed substrate tester (HSST) which hastraditionally been characteristically large and slow.

Features on MLC substrates are very small and in close proximity to oneanother. For example, any one particular MLC substrate may include morethan one thousand pin or pad connections in an area on the order ofone-quarter square inch of space, as can been realized in the currentstate of art for MLC substrates. It is thus very critical to align thesubstrate parts in a repeatable manner, for example, with respect to atesting and a placement of test contacts, or other processing andmanufacturing options, such as chip placement, discrete wiring, etc.

U.S. Pat. No. 4,436,385, issued Mar. 13, 1984 and entitled "SpecimenHolder for Inverted Microscopes" discloses a specimen holder having awide range of capability for replaceably accepting and holding any oneof a variety of sizes and shapes of specimens. In one embodiment, thespecimen holder includes a release and clamp mechanism for one-handedoperation. A series of interconnected mechanical links are disposedbetween a first plate and a second plate. The interconnected links pivotwith respect to each other at their respective interconnections.Furthermore, one of the interconnected links includes a pin and slotconnection to one of the plates, which further pivots about a pivotpoint for moving the plates towards each other or away from one anothervia the multiple interconnected links. However, a given amount ofmovement in one direction by the pin and slot connected linkage does notproduce a corresponding same amount of movement of the correspondingconnected plate when the pin and slot connected linkage is moved thesame given amount in an opposite direction. Accurate determinablepositioning is thus not attainable. This is because the specimen holdersuffers from an undesirable buildup of tolerances as a result of themultiple interconnected linkages and the slot and pin connection.Non-uniform plate movement further results in a different centerlinelocation for each successive clamped specimen. In addition, not all ofthe components of the specimen holder are in tension during a clampingoperation, thus the specimen being clamped is subject to a non-uniformclamping force and possible mis-positioning.

It would thus be desirable to provide a locator which can accuratelylocate and repeatably position MLC substrates with respect to acenterline location during a manufacturing process, and furthermore,reduce the manufacturing costs of producing the same.

SUMMARY OF THE INVENTION

An object of the present invention is to provide substrate locator whichaddresses current manufacturing requirements in terms of repeatability,accuracy, and cost efficiency and overcomes problems in the art asdiscussed herein above.

Another object of the present invention is to more accurately locate andposition substrates during a manufacturing process and to reducemanufacturing costs overall.

According to the present invention, an apparatus for locating aworkpiece on a processing surface includes a first locator arm assemblyhaving a first surface disposed for lateral movement and matingengagement with a first portion of the workpiece. A second locator armassembly includes a second surface disposed for lateral movementparallel to the first surface. The second surface is for matingengagement with a second, opposite side, portion of the workpiece.Lastly, a pivotal means is disposed for pivotal movement about a pivotpoint and symmetrically coupled, with a zero tolerance buildup, betweenthe first locator arm assembly and the second locator arm assembly. Thepivotal means is for inducing an equal but opposite lateral movement inthe first and second mating engagement surfaces of the first and secondlocator arm assemblies, respectively, whereby the workpiece isaccurately located on the processing surface between respective firstand second mating engagement surfaces as the surfaces are moved towardsone another.

Further in accordance with the present invention, a method of locating aworkpiece on a processing surface includes the steps of providing afirst locator arm assembly having a first surface disposed for lateralmovement and mating engagement with a first portion of the workpiece. Asecond locator arm assembly having a second surface disposed for lateralmovement parallel to the first surface is provided, the second surfacefurther for mating engagement with a second, opposite side, portion ofthe workpiece. Lastly, a pivotal means is provided which is disposed forpivotal movement about a pivot point and symmetrically coupled, with azero tolerance buildup, between the first locator arm assembly and thesecond locator arm assembly for inducing an equal but opposite lateralmovement in the first and second mating engagement surfaces of the firstand second locator arm assemblies, respectively. As a result, theworkpiece is accurately located on the processing surface betweenrespective first and second mating engagement surfaces as the surfacesare moved towards one another.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other teachings and advantages of the presentinvention will become more apparent upon a detailed description of thebest mode for carrying out the invention as rendered below. In thedescription to follow, reference will be made to the accompanyingdrawings, where like reference numerals are used to identify like partsin the various views and in which:

FIG. 1 shows a top view of an MLC substrate having been positioned upona processing surface by the locator according to the present invention;

FIG. 2 illustrates a top view of the present invention in accordancewith a first embodiment;

FIG. 3 illustrates a side view of the embodiment of the presentinvention as shown in FIG. 2;

FIG. 4 shows a top view of the embodiment of the present invention asshown in FIG. 2 having mating engagement surfaces in an open position;

FIG. 5 illustrates an alternate embodiment of the present invention;

FIG. 6 illustrates an exploded perspective view of the alternateembodiment of FIG. 5; and

FIG. 7 illustrates yet another alternate embodiment according to thepresent invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION

Turning now to the FIG. 1, a top view of a substrate processingapparatus 10 according to one embodiment of the present invention isshown. Substrate processing apparatus 10 includes a locator apparatus 12for locating a substrate 14, for example, an MLC substrate, on aprocessing surface 16 during a processing operation. Processing surface16 may include, for example, any suitable platen or other surface. Acenter of the substrate 14 can be accurately and repeatably positionedand located over a desired nesting point 18 on the processing surface16, regardless of any variations in the size of the MLC substrate beinglocated upon the processing surface 16. As shown, a pair of locator jaws20a and 20b of the locator apparatus 12 according to the presentinvention locate the substrate 14 from opposite side edges, and moreparticularly, opposite corner edges thereof. The pair of locator jaws20a and 20b further extend through apertures 22a and 22b, respectively,in the processing surface 16 and above the surface in a verticaldirection by an amount sufficient for engaging substrate 14. Furtherdetails of the locator apparatus 12 shall be described herein below.

Turning now to FIGS. 2 and 3, which exemplify a top view and side view,respectively, of the locator apparatus 12, locator apparatus 12 includesa first locator arm assembly 30, a second locator arm assembly 32, and apivotal means 34 disposed for pivotal movement about a pivot point 38and symmetrically coupled, with a zero tolerance buildup, between thefirst locator arm assembly 30 and the second locator arm assembly 32.First locator arm assembly 30, second locator arm assembly 32, andpivotal means 34 can be mounted upon a base plate 36 is a desiredspatial relationship and/or configuration, for example, as shown anddiscussed further herein below.

First locator arm assembly 30 includes a first linear slide mechanism40a having a first locator arm 42a slidably mounted thereon fortranslational movement. The first locator arm 42a has a first surface44a disposed for lateral movement and mating engagement with a firstportion 14a of the substrate 14. Second locator arm assembly 32 includesa second linear slide mechanism 40b having a second locator arm 42bslidably mounted thereon for translational movement, the translationalmovement being parallel to the translational movement of the firstlocator arm 42a. The second locator arm 42b has a second surface 44bwhich is disposed for lateral movement parallel to the first surface44a. The second surface 44b is further for mating engagement with asecond, opposite side, portion 14b of the substrate 14. Preferably, thefirst and second mating engagement surfaces 44a and 44b, respectively,each include a square or right angle surface, hereinafter referred to asa V-shape engagement surface. In addition, the V-shape engagementsurfaces each include a relief bore at the bottom of the V-shape forreceiving a corner of the substrate or workpiece therein during alocating of the substrate or workpiece to insure side contact.

Linear slide mechanisms 40a and 40b, preferably include microfrictionless precision linear slides, such as those commerciallyavailable by Schneeburger of Bedford, Mass, U.S.A., for example, Model#ND3-105.60. Linear slide mechanisms 40a and 40b are mounted oppositeone another, with their respective sliding motion running parallel toeach other. Furthermore, slide mechanisms 40a and 40b are mounted tobase plate 36 by suitable fasteners.

Referring still to FIGS. 2 and 3, pivotal means 34 is disposed forpivotal movement on base plate 36 about a pivot point 38. Pivotal means34 is further symmetrically coupled, with a zero tolerance buildup,between the first locator arm assembly 30 and the second locator armassembly 32 for inducing an equal but opposite lateral movement in thefirst and second mating engagement surfaces 44a and 44b of the first andsecond locator arm assemblies 30 and 32, respectively. Preferably,pivotal means 34 includes a pivotal arm member or block 50 symmetricallycoupled to the first and second locator arms 42a and 42b using flatsprings 52a and 52b, respectively.

Pivotal arm member 50 preferably includes a precision bearing 54 forpivotal movement about pivot point 38.

Precision bearing 54 includes, for example, a precision bearing such asa shaft and bushing with a close running fit. The precision bearingcreates a minimal tolerance between pivot point 38 and pivotal armmember 50 in accordance with a particular precision bearing used, whichadds minimal, if any, tolerance build up to the overall locatorapparatus 12.

Flat springs 52a and 52b are fixedly attached or fastened (i.e.,sandwiched solidly) between opposite ends of the pivotal arm member 50and corresponding first and second locator arm assemblies 30 and 32,respectively, using suitable fastening means, such as clamping platesand fasteners 63, 64, 65, and 66. Flat springs 52a and 52b are thussolidly located. Flat springs or shims 52a and 52b are preferablyfabricated from flat high carbon spring stock, typically 0.010" thick by0.50" wide (scaled appropriately for use with the particular precisionslide used, such as Schneeburger Model No. ND3-105.60).

In accordance with the present invention, substrate 14 can be accuratelylocated on the processing surface 16 between respective first and secondmating engagement surfaces 44a and 44b as the surfaces are moved towardsone another.

Further with respect to the embodiment as shown in FIGS. 2 and 3, aspring 60 having a desired tension is provided. Spring 60 is fastenedbetween a raised block portion 36a of base 36 and the first locator arm42a, by suitable means, such as shoulder screws 62. Spring 60 is usedfor exerting a pulling force F1 on the first locator arm 42a which isfastened to linear slide mechanism or slide 40a. The pulling force F1causes the first locator arm 42a to be biased for movement in thedirection of force F1, which further, also causes locator arm jaw 20aand mating engagement surface 44a to move in a "close₁ " direction.

The first locator arm 42a is connected to pivotal arm member or block 50at a first end 51a thereof by flat spring 52a, using a suitable clampplate and fastener. An opposite end 51b of pivotal arm member 50 isconnected to the second locator arm 42b by a similar flat spring 52b,using a suitable clamp plate and fastener. Pivotal arm member 50 isfurther free to rotate about a pivot point 38 using precision bearing54.

The second locator arm 42b is fastened by suitable means to a linearstage of slide mechanism or slide 40b and is free to move with thelinear stage of slide 40b. The spring pulling force F1 further causespivotal arm member 50 to rotate counter clockwise (as indicated by thearrow marked CC in FIG. 2) resulting in the second locator arm 42b beingbiased for movement in an opposite direction of force F1, which further,also causes locator arm jaw 20b and mating engagement surface 44b tomove in the "close₂ " direction. Both locator arm jaws 20a and 20bconverge on and clamp a typical substrate 14 when the pair of jaws aremoving in the respective "close" direction. Pivotal arm member 50 issymmetrical by design so that any rotational motion will cause eachlocator arm jaw 20a and 20b to move uniformly in an opposite direction,either towards one another or away from one another. In other words, anymovement of locator arm jaw 20a in a first translational direction willresult in an equal movement of locator arm jaw 20b in an oppositetranslational direction.

To release or unclamp substrate 14, a force F2 (as shown by the arrowlabeled F2 in FIG. 2) is applied by any suitable means. The magnitudeforce F2 is required, at a minimum, to be sufficient enough to causepivotal arm member 50 to rotate clockwise, as noted in FIG. 2 by thearrow labeled "C", to thus move the pair of first and second locatorjaws 20a and 20b, respectively, in an "open" direction. It is preferablethat an "open" position correspond to a position of the jaws which issufficient for the substrate to clear the outermost portion of theengagement surfaces of the respective jaws as the substrate is placedupon and/or removed from the nesting location on the processing surface16.

Spring 60 provides a force of a sufficient tension to allow locator arm42a on slide mechanism 40a to move to the right, into a position asshown in FIG. 2. As a result, the pivotal arm member 50 is pulled in acounter clockwise direction "CC" via the zero tolerance build up,solidly located connection flat spring 52a. The pivotal arm member 50 isallowed to rotate on it's central axis 38 by precision bearing 54. Inconjunction with the rotation of pivotal arm member 50, flat spring 52bwill pull locator arm 42b on slide mechanism 40b exactly the samedistance as locator arm 42a moves on slide mechanism 40a in an oppositedirection.

Referring now to FIG. 4, the motion can be reversed by applying a forceF2 to the locator arm 42a on slide mechanism 40a in the oppositedirection of F1 so as to counter act the tension force of spring 60.Alternatively, the force F2 may be applied to locator arm 42b on slidemechanism 40b to the right to create the same effect. Still further,spring 60 may be replaced by any suitable means which is configured tomove and provide a first "opening" force and a second "closing" forcenecessary to actuate a locating and positioning operation of the locatorapparatus of the present invention. As shown in FIG. 4, force F2 causespivotal arm member 50 to rotate in a clockwise direction which furthercauses flat springs 52a and 52b to flex accordingly. As a result, a zerotolerance build-up, exact movement of jaws 20a and 20b is achieved.

The first and second locator jaws 20a and 20b are preferably part of arespective first and second locator arm 42a and 42band/or appropriatelyconnected thereto. The flat springs 52A and 52B are mounted torespective locator arms 42a and 42b in such a way (with clamp plates 63,64, 65, and 66) such that they perform like "living hinges". The flatsprings 52A and 52B provide a zero tolerance and positioningrepeatability. Any movement of one locator jaw will cause an identicalmovement of the other locator jaw in the opposite direction. Forexample, if pivotal arm member 50 is rotated counter clockwise a varyslight amount so as to cause locator jaw 20a to move 0.0001 inch towardsthe right, then locator jaw 20b would move exactly 0.0001 inch towardsthe left. The present invention is thus highly useful in automationcontrolled handling applications requiring accurate and repeatablepositioning of substrates or workpieces.

As mentioned herein above, locator arm members 42a and 42b are mountedon slide mechanisms 40a and 40b, respectively, further wherein locatorarm members 42a and 42binclude locator jaws 20a and 20b, respectively.Jaws 20a and 20b are used for locating and positioning a generallysquare substrate 14 precisely over, under, or between a particularsubstrate process station or stations, as the case may be. Locating andpositioning of the substrates can be in preparation for purposes oftesting, inspecting, and/or other applications, for example, wherein theapplications may require the attaching of components precisely.

Rectangular parts may likewise be located and positioned with thelocator apparatus of the present invention. In this later instance, therectangular substrate or part can be clamped by off-setting a centerlineC_(L) of the V-shape notch of each of the jaws 20a and 20b to fit theprofile of the part being clamped. In other words, the centerline C_(L)of each V-notch of the jaws is off-set or displaced in a parallel mannera desired distance from one another. In the preferred embodiment, thecenterline C_(L) of each of the V-shaped notches of the jaws 20a and 20bare aligned and co-extensive.

The present invention thus provides a more accurate positioning systemthan prior known systems, and furthermore, the locator apparatus of thepresent invention is fabricated using a minimum of parts. The presentinvention further provides an overall much smaller package than priorknown locator systems, thus reducing, for example, an amount of factoryfloor space required, and allowing a greater flexibility to the designof manufacturing and process equipment within the confines of thesubstrate locator.

Many configurations of the slide mechanism placement, with respect tothe other slide mechanism, are possible to accomplish a similar effect.For example, in accordance with an alternate embodiment according to thepresent invention, as shown in FIGS. 5 and 6, the pivot means 34 isplaced in between the slide mechanisms 140a and 140b. A force F3 isapplied to the pivotal arm member 150 to keep flat springs 152a and 152bin tension. Force F3 can be provided, for example, by compression spring60 attached between an extension off of pivot member 50 and mechanicalground, wherein flat springs 152a and 152b held in tension.

An advantage of the present invention is that the flat springs aresolidly located to the pivotal arm member and the locator arms on theslide mechanisms, thus no tolerance buildup is realized betweenrespective locator arm assemblies and the pivotal arm member.Effectively, an overall minimal or zero tolerance build up is obtained.Furthermore, the present invention provides an improved positioningaccuracy with simplicity.

Yet another advantage of the present invention is that all componentsare in tension during a locating, positioning, and clamping process. Theeffect of having all components under tension during the clampingprocess is that it provides an equal and uniform force exerted on theclamped part with no chance of distortion due to deflection.

The present invention advantageously overcomes the problems encounteredwith current technology four-point locators, the later of which arecomprised of many moving parts which leads to tolerance build-ups,inaccuracies and increased costs. The present invention is more accuratein locating and positioning of MLC substrates, as well as otherworkpieces, and further provides for overall reduced manufacturingcosts.

With respect to the present invention, the jaws can locate and positionsquare or round substrates or other workpieces. In accordance with thepresent invention, substrates are supported on an independent nest,corresponding to a portion of processing surface 16 (FIG. 1), whereinthe nest is centered between the jaws. Locating a substrate over thetrue center of the nesting point exactly, regardless of the substrate'ssize, is accomplished with the locator apparatus of the presentinvention. With the locator apparatus of the present invention, the truecenter of the substrate is caused to overlay the true center of thenest. Furthermore, the present invention provides a positioningrepeatability and accuracy on the order of less than 1 micron of truecenter for locating a substrate. The tolerance build up of the fourpoints as discussed with respect to the related art is eliminated by thefixed ends of the flexing "shims" connection of the pivotal arm memberand the locator arm members on the respective slide mechanisms. Thesolidly located flat spring feature, as discussed herein, guarantees theaccurate repeatability.

Referring now to FIG. 7, an alternate embodiment according to thepresent invention is similar to the embodiment as shown with respect toFIGS. 2-4, with the following differences, wherein the alternateembodiment is suitable for the positioning and locating of relativelylarge substrates. The positioning, locating and clamping apparatus 12bincludes an enlarged aperture 70 in base plate 36. Aperture 70 enables aprobing from an underside of a substrate under test, when located andpositioned with locator jaws 20a and 20b. Locator jaws 20a and 20b aremounted upon locator arm members 142a and 142brespectively. In additionto precision slide mechanisms 142a and 142ba third precision slidemechanism 142c is provided. An rigid extension bar member 72 is solidlyconnected between the stage of the third slide mechanism 142c and thestage of second slide mechanism 142b. Any movement of the stage of slidemechanism 142c is equally transferred to the stage of slide mechanism142b.

Tension spring 60 provides a proper amount of tension for a substrateclamping force. Placement of the tension spring 60 is such that the flatsprings are always maintained in tension when clamping a substrate orworkpiece (as opposed to being in compression). When in tension, theflat springs are equal in geometry on both sides. In addition, whenclamping a substrate, it is preferred to have the flat springs be in agenerally flat position. However, when the flat springs are incompression, one flat spring may be weaker than the other, thusresulting in a non-uniform deflection or spring action. When opening upthe locator jaws to insert a substrate there between, the flat springscan bend and flex in accordance with appropriate pivotal movement of thepivot member, placing the flat springs under compression. In the absenceof the spring force F3 provided by spring 60, when the flat springs areflat, the substrate is to fit within locator jaws with a tolerance onthe order of a few thousandths of an inch to prevent any unnecessarybending on the flat springs themselves. Only when advanced in a forwardclosing position and tension is put onto the substrate, does thesubstrate become absolutely centered. The force exerted upon thesubstrate by the locator jaws is sufficient to hold the same in adesired vertical position during a testing operation.

The embodiment of the present invention as shown in FIG. 7 thus providesfor the positioning, locating, and clamping of larger substrates. Inaddition, apparatus 12c is suitable for testing operations requiring theadministration of process operations to the substrate from below andabove.

According to the present invention, a method of locating a workpiece ona processing surface includes the steps of providing a first locator armassembly having a first surface disposed for lateral movement and matingengagement with a first portion of the workpiece. A second locator armassembly is provided, the second locator arm assembly having a secondsurface disposed for lateral movement parallel to the first surface. Thesecond surface is further for mating engagement with a second, oppositeside, portion of the workpiece. Lastly, a pivotal means is disposed forpivotal movement about a pivot point and symmetrically coupled, with azero tolerance buildup, between the first locator arm assembly and thesecond locator arm assembly. The pivotal means is further provided forinducing an equal but opposite lateral movement in the first and secondmating engagement surfaces of the first and second locator armassemblies, respectively, whereby the workpiece is accurately located onthe processing surface between respective first and second matingengagement surfaces as the surfaces are moved towards one another. Thepivotal means further includes a pivotal arm member symmetricallycoupled between the first locator arm assembly and the second locatorarm assembly using flat springs solidly located between opposite ends ofthe pivotal arm member and corresponding first and second locator armassemblies, respectively.

In one embodiment of the method of present invention, the first locatorarm assembly includes a first linear slide mechanism having a firstlocator arm slidably mounted thereon. The first locator arm includes thefirst mating engagement surface. The second locator arm assemblyincludes a second linear slide mechanism having a second locator armslidably mounted thereon, wherein the second locator arm including thesecond mating engagement surface. Furthermore, the pivotal meansincludes a pivotal arm member symmetrically coupled between the firstlocator arm assembly and the second locator arm assembly using flatsprings solidly located between opposite ends of the pivotal arm memberand corresponding first and second locator arm assemblies, respectively.

The method of the present invention further includes providing a baseplate. In this instance, the first locator arm assembly includes a firstlinear slide mechanism having a base fixedly attached to the base plate.The first linear slide mechanism further includes a first locator armslidably mounted thereon for lateral movement. The second locator armassembly includes a second linear slide mechanism having a base fixedlyattached to the base plate. The second linear slide mechanism furtherincludes a second locator arm slidably mounted thereon for lateralmovement.

Further in accordance with one embodiment according to the presentinvention, the first and second mating engagement surfaces each includea V-shape engagement surface. The V-shape engagement surface may furtherinclude a relief bore at the bottom of the V-shape for receiving acorner of the workpiece therein during a locating of the workpiece.

The method of locating a substrate or workpiece further includesdisposing one of the first locator arm assembly, the second locator armassembly, and the pivotal means between a first position and a secondposition, thereby effecting a movement of the first mating engagementsurface and the second mating engagement surface between an openposition and a closed position, respectively. Still further, the methodincludes spring biasing one of the first locator arm assembly, thesecond locator arm assembly, and the pivotal means in a manner forcausing the first mating engagement surface and the second matingengagement surface to be displaced towards one another in a closedposition in an absence of other outside biasing forces. Alternatively,the spring biasing of one of the first locator arm assembly, the secondlocator arm assembly, and the pivotal means can similarly be in a mannerfor causing the first mating engagement surface and the second matingengagement surface to be displaced away from one another in an openposition in an absence of other outside biasing forces.

Still further, a substrate is located on a processing surface during aprocessing operation, by a method of providing a first locator armassembly including a first linear slide mechanism having a first locatorarm slidably mounted thereon. The first locator arm includes a firstsurface disposed for lateral movement and mating engagement with a firstportion of the substrate. A second locator arm assembly including asecond linear slide mechanism having a second locator arm slidablymounted thereon is provided, wherein the second locator arm includes asecond surface disposed for lateral movement parallel to the firstsurface. The second surface is further for mating engagement with asecond, opposite side, portion of the substrate. Lastly, a pivotal meansis provided which is disposed for pivotal movement about a pivot pointand symmetrically coupled, with a zero tolerance buildup, between thefirst locator arm assembly and the second locator arm assembly. Thepivotal means is for inducing an equal but opposite lateral movement inthe first and second mating engagement surfaces of the first and secondlocator arm assemblies, respectively. Furthermore, the pivotal meansincludes a pivotal arm member symmetrically coupled using flat springssolidly located between opposite ends of the pivotal arm member andcorresponding first and second locator arm assemblies, respectively,whereby the substrate is accurately located on the processing surfacebetween respective first and second mating engagement surfaces as thesurfaces are moved towards one another.

While the invention has been particularly shown and described withreference to specific embodiments thereof, it will be understood bythose skilled in the art that various changes in form and detail may bemade thereto, and that other embodiments of the present invention beyondembodiments specifically described herein may be made or practicewithout departing from the spirit of the invention, as limited solely bythe appended claims.

What is claimed is:
 1. An apparatus for locating a workpiece on aprocessing surface, said apparatus comprising:first locator arm assemblyhaving a first surface disposed for lateral movement and matingengagement with a first portion of the workpiece; second locator armassembly having a second surface disposed for lateral movement parallelto the first surface, the second surface further for mating engagementwith a second, opposite side, portion of the workpiece; and pivotalmeans disposed for pivotal movement about a pivot point andsymmetrically coupled, with a zero tolerance buildup, between said firstlocator arm assembly and said second locator arm assembly for inducingan equal but opposite lateral movement in the first and second locatorarm assemblies, respectively, wherein said pivotal means includes apivotal arm member symmetrically coupled using flat springs solidlylocated between opposite ends of the pivotal arm member andcorresponding first and second locator arm assemblies, respectively,whereby the workpiece is accurately located on the processing surfacebetween respective first and second mating engagement surfaces as thesurfaces are moved towards one another.
 2. The apparatus of claim 1,further comprisinga base plate, further wherein said first locator armassembly includes a first linear slide mechanism having a base fixedlyattached to said base plate, the first linear slide mechanism furtherhaving a first locator arm slidably mounted thereon for lateralmovement, the first locator arm including the first mating engagementsurface; and said second locator arm assembly-includes a second linearslide mechanism having a base fixedly attached to said base plate, thesecond linear slide mechanism further having a second locator armslidably mounted thereon for lateral movement, the second locator armincluding the second mating engagement surface.
 3. The apparatus ofclaim 1, whereinthe first and second mating engagement surfaces reachinclude a V-shape engagement surface.
 4. The apparatus of claim 3,further whereinthe V-shape engagement surface includes a relief bore atthe bottom of the V-shape for receiving a corner of the workpiecetherein during a locating of the workpiece by said locator apparatus. 5.The apparatus of claim 1, further comprising:means for disposing one ofsaid first locator arm assembly, said second locator arm assembly, andsaid pivotal means between a first position and a second position,thereby effecting a movement of the first mating engagement surface andthe second mating engagement surface between an open position and aclosed position, respectively.
 6. The apparatus of claim 1, furthercomprisingmeans for spring biasing one of said first locator armassembly, said second locator arm assembly, and said pivotal means in amanner for causing the first mating engagement surface and the secondmating engagement surface to be displaced towards one another in aclosed position in an absence of other outside biasing forces.
 7. Theapparatus of claim 1, further comprisingmeans for spring biasing one ofsaid first locator arm assembly, said second locator arm assembly, andsaid pivotal means in a manner for causing the first mating engagementsurface and the second mating engagement surface to be displaced awayfrom one another in an open position in an absence of other outsidebiasing forces.
 8. A substrate processing apparatus having a locator forlocating a substrate on a processing surface during a processingoperation, said apparatus comprising:first locator arm assemblyincluding a first linear slide mechanism having a first locator armslidably mounted thereon, the first locator arm having a first surfacedisposed for lateral movement and mating engagement with a first portionof the substrate; second locator arm assembly including a second linearslide mechanism having a second locator arm slidably mounted thereon,the second locator arm having a second surface disposed for lateralmovement parallel to the first surface, the second surface further formating engagement with a second, opposite side, portion of thesubstrate; and pivotal means disposed for pivotal movement about a pivotpoint and symmetrically coupled, with a zero tolerance buildup, betweensaid first locator arm assembly and said second locator arm assembly forinducing an equal but opposite lateral movement in the first and secondmating engagement surfaces of said first and second locator armassemblies, respectively, wherein said pivotal means includes a pivotalarm member symmetrically coupled using flat springs solidly locatedbetween opposite ends of the pivotal arm member and corresponding firstand second locator arm assemblies, respectively, whereby the substrateis accurately located on the processing surface between respective firstand second mating engagement surfaces as the surfaces are moved towardsone another.